These nymphs are a modern staple. Frenchies take the simple imitation ability of a Pheasant Tail Nymph, and place a modernized hot spot as a collar. They look a little bit like anything and everything.
If I'm fishing new water there's no doubt I'm going to have several of these in my box. 
Sz. 14 hooks have a 3.3mm tungsten slotted bead. 
Sz. 12 hooks have a 3.8mm tungsten slotted bead.